In a conventional synchronous mobile telecommunication system, a synchronous mobile station is connected to a synchronous radio network (for example, a CDMA-2000 radio network), and an ANSI-41 network is connected to a core network.
In a conventional asynchronous mobile telecommunication system, an asynchronous mobile station is connected to an asynchronous radio network (for example, a UMTS (universal mobile telecommunications system) Terrestrial Radio Access Network (UTRAN)), and a global system for mobile communications-mobile application part (GSM-MAP) network is connected to a core network.
FIG. 1 shows core network interface architectures of the conventional synchronous/asynchronous mobile telecommunication systems as mentioned above.
FIG. 1A is a view showing the core network interface architecture of the conventional synchronous mobile telecommunications system. In this drawing, the reference numeral 110 denotes a synchronous mobile station, 120 denotes a synchronous radio network (e.g., a code division multiple access-2000 (CDMA-2000) radio network) which performs a data interfacing operation with the synchronous mobile station 110 and includes a synchronous base transceiver station/base station controller (BTS/BSC), and 130 denotes a synchronous core network which is connected to the synchronous radio network 120 and includes a synchronous mobile services switching center (MSC) 131 and an ANSI-41 network 133.
In the above core network interface architecture of the conventional synchronous mobile telecommunication system, the synchronous mobile station 110 can be connected to only the synchronous radio network 120 as well known to one skilled in the art, which is in turn connected to the synchronous core network 130, thereby allowing the synchronous mobile station 110 to be interfaced with only the synchronous core network 130.
FIG. 1B is a view showing the core network interface architecture of the conventional asynchronous mobile telecommunication system. In this drawing, the reference numeral 140 denotes an asynchronous mobile station, 150 denotes an asynchronous radio network (i.e., a UTRAN) which includes a base transceiver station (BTS) and a radio network controller (RNC), and 160 denotes an asynchronous core network which includes an asynchronous mobile services switching center (MSC) 161 connected to the asynchronous radio network 150 and a GMS-MAP network 163 connection to the asynchronous MSC 161.
In the above core network interface architecture of the conventional asynchronous mobile telecommunications system, the asynchronous mobile station 140 is connected to the asynchronous radio network 150 (e.g., UTRAN) which is in turn connected to the asynchronous core network 160, thereby allowing the asynchronous mobile station 140 to perform a data interfacing operation with the asynchronous core network 160.
FIG. 2 shows layer protocol structures of the conventional mobile telecommunication systems as mentioned above.
FIG. 2A is a view showing the layered protocol structure of the conventional synchronous mobile telecommunications system. In this drawing, the reference numeral 110 denotes a synchronous mobile station, 120 a synchronous radio network and 50 a synchronous core network connected to the synchronous radio network 130.
The synchronous mobile station 110 comprises a layer3 111, a layer2 114 and a layer1 115. The layer3 111 includes a synchronous call control (CC) entity 113 for a call management and a synchronous mobility management (MM) entity 112 for a mobility management.
The layer1 115 is a physical layer which offers data transport services to higher layers and transfers transport blocks over a radio interface.
The layer2 114 is a data link layer which includes the following sub layers, a medium access control (MAC) sub layer and a radio link control (RLC) sub layer. However, the sub layers are not shown in this drawing.
The MAC sub layer offers data transfer services on logical channels to a higher layer, the RLC sub layer, and on transport channels to a lower layer, the physical layer 36. The MAC sub layer is responsible for mapping of the logical channel onto the appropriate transports channel.
The RLC sub layer offers data transfer services on primitive to a higher layer and on logical channels to a lower layer, MAC sub layer. Also, the RLC sub layer performs an error correction, a duplicate detection, a ciphering and a flow control of the data.
The layer3 114 is a network layer which includes the following sub layers, a synchronous radio resource (RR) sub layer, a synchronous call control (CC) entity 113 and a mobility management (MM) entity 112. In the synchronous system, the synchronous RR sub layer is not apparently separated from the others in the layer3 111.
The RR sub layer offers data transfer services on primitive to a lower layer, RLC sub layer, and handles a control plane signaling of the layer3 111 between a mobile station and a synchronous radio network. The RR sub layer manages a radio resource. Also, the RR sub layer assigns/re-configures/releases the radio resource to the mobile station/radio network.
The CC entity 113 handles a call control signaling of layer3 between the mobile stations and the synchronous radio network.
The MM entity 112 handles a mobility management signaling of layer 3 between the mobile stations and the synchronous radio network.
The layers 3 to 1 111, 114 and 115 in the synchronous mobile station 110 communicate with corresponding layers 121, 122 and 123 in the synchronous radio network 120.
The synchronous radio network 120 comprises a layer3 121, a layer2 122 and a layer 1 123. The layers 3 to 1 121, 122 and 123 in the synchronous radio network 120 correspond respectively to those in the synchronous mobile station 110.
The layers 3 to 1, 121, 122 and 123 in the synchronous radio network 120 communicate with corresponding layers in the synchronous mobile station 110 and the synchronous core network 130.
The synchronous core network 130 comprises a layer3 131, a layer2 134 and a layer 1 135. The layers 3 to 1 in the synchronous radio network 130 correspond respectively to those in the synchronous radio network 120.
The layers 3 to 1 131, 134 and 135 in the synchronous core network 130 communicate with corresponding layers 121, 122 and 123 in the synchronous radio network 120.
In the conventional synchronous mobile station and radio network as the layered protocol structure, the synchronous mobile station 110 receives a Sync channel message from the synchronous radio network 120 over a Synch channel and acquires information necessary to its connection to the synchronous core network 130, including information related to the synchronous core network 130 and information about the synchronous radio network 120, from the received Sync channel message.
In other words, for interfacing with the synchronous ANSI-41 network via the synchronous radio network, the synchronous mobile station acquires system information (i.e., information related to the radio network and core network) after it is powered on.
Information elements are written in the Sync channel message received by the synchronous mobile station, as follows:
a) Protocol Revision Level: 8 bits,
b) Minimum Protocol Revision Level: 8 bits,
c) System Identification: 15 bits,
d) Network Identification: 16 bits,
e) Pilot Pseudo Noise (PN) sequence offset index: 9 bits,
f) Long Code State: 42 bits,
g) System Time: 36 bits,
h) The number of Leap seconds that have occurred since the start of System Time: 8 bits,
i) Offset of local time from System Time: 6 bits,
j) Daylight savings time indicator: 1 bit,
k) Paging Channel data Rate: 2 bits,
l) Frequency assignment: 11 bits,
m) Extended frequency assignment: 11 bits, and
n) Orthogonal transmit diversity mode: 2 bits.
The synchronous mobile station stores the following information elements from the received Sync channel message in its memory:
a) Protocol Revision Level: 8 bits,
b) Minimum Protocol Revision Level: 8 bits,
c) System Identification: 15 bits,
d) Network Identification: 16 bits,
e) Pilot PN sequence offset index: 9 bits,
f) Long Code State: 42 bits,
g) System Time: 36 bits,
h) Paging Channel Data Rate: 2 bits, and
i) Orthogonal transmit diversity mode: 2 bits.
FIG. 2B is a view showing the layered protocol structure of the conventional asynchronous mobile telecommunications system. In this drawing, the reference numeral 140 denotes an asynchronous mobile station, 150 an asynchronous radio network (e.g., UTRAN) and 160 an asynchronous core network.
The asynchronous mobile station 140 comprises a non-access stratum (NAS) part, a layer3 144, a layer2 145, and a layer1 146. In particular, the layer3 144 includes an access stratum (AS) part. The NAS part includes an asynchronous call control (CC) entity 143 for management of a call and an asynchronous mobility management (MM) entity 142 for management of a mobility. The AS part includes an asynchronous radio resource control (RRC) block. In the asynchronous system, the asynchronous RRC sub layer is apparently separated from the NAS part. Functions of the asynchronous RRC sub layer are the same as those of the synchronous RR sub layer.
The asynchronous radio network 150 comprises a layer3 151, a layer2 152, and a layer1 153. The layer3 151 of the asynchronous radio network 150 has no NAS part having an asynchronous CC entity and an asynchronous MM entity. The layers 3 to 1 of the asynchronous radio network 150 are connected and correspond respectively to those in the asynchronous mobile station 140 and those in the asynchronous core network 160. However, since the asynchronous radio network 150 does not have the NAS part, i.e., the asynchronous CC entity and the asynchronous MM entity, the NAS parts of the asynchronous mobile station 140 and asynchronous core network 160 are coupled to each other not through the asynchronous radio network 150.
The asynchronous core network 160 comprises a NAS part 161 connected to that of the asynchronous mobile station 140, a layer3 164 having a AS part (not shown in FIG. 2B), a layer2 165 and a layer 1 166 connected respectively to those in the asynchronous radio network 150. The NAS part comprises an asynchronous CC entity 163 for management of a call and an asynchronous MM entity 162 for management of mobility.
Functions of the layer 3 to 1 of the asynchronous system are similar with those of the synchronous system except for an operating type. Therefore, for convenience, detailed description of the layer 3 to 1 will be skipped.
The more detailed descriptions about layered protocol structures are well taught in 3rd Generation partnership Project (3GPP), Technical Specification group (TSG)-Radio Access Network (RAN): 3G TS25.301 (Radio Interface Protocol Architecture), 3G TS25.302 (Services provided by the physical layer), 3G TS25.321 (MAS Protocol Specification), 3G TS25.322 (RLC Protocol Specification) and 3G TS25.331 (RRC Protocol Specification) in detail.
In the conventional asynchronous mobile station and radio network having the layered protocol structure, the asynchronous mobile station 140 receives a system information message from the asynchronous radio network 150 over a broadcast control channel (BCCH) and acquires information necessary to its connection to the asynchronous core network 160, including information related to the asynchronous core network 160 and information about the asynchronous radio network 150, from the received system information message.
IMT-2000 systems are the third generation systems which aim to unify the various mobile communication networks and services into one to provide many mobile communication services. The systems can provide multimedia services under multi-environments through various air-interfaces and high capacity. Also, in the aspect of services, the systems can provide multimedia services of speech, image and data up to the rate of 2 Mbps and international roaming. And, in the aspect of network, the systems are total systems which are based on ATM networks and combine fixed and wireless systems.
IMT-2000 system requires new system concept, a high-level adaptation technology, and a novel network technology, as well all conventional technologies which were already adopted in the second digital cellular system.
As described above, in the next-generation mobile telecommunication system such as the IMT-2000 system, either the GSM-MAP network used in the above conventional asynchronous mobile telecommunications system or the ANSI-41 network used in the above conventional synchronous mobile telecommunications system should be employed as a core network in order to perform an international roaming in a synchronous or asynchronous mobile telecommunications system of an IMT-2000 system.
According to network deployment scenarios, the IMT-2000 system can have the following four interface architectures; first: synchronous mobile station—synchronous radio network—synchronous ANSI-41 network, second: synchronous mobile station—synchronous radio network—asynchronous GSM-MAP network, third: asynchronous mobile station—asynchronous radio network—synchronous ANSI-41 network, and fourth: asynchronous mobile station—asynchronous radio network—asynchronous GSM-MAP network.
FIG. 3 is a view showing a protocol stack structure for interfacing a mobile station and a base station with a core network in a next-generation mobile telecommunications system.
Referring to FIG. 3, it is illustrated a protocol stack structure for interfacing a mobile station and a base station with a core network having the same or a different operating type with/from the mobile station and the base station in a next-generation mobile telecommunications system such as the IMT-2000 system.
The asynchronous mobile station includes a physical layer, a medium access layer, a radio link layer, a radio resource layer, a mobility management entity and a call control entity. Also, the asynchronous mobile station includes extensions and hooks.
The extension performs a mapping function between the asynchronous mobile station and the synchronous core network. The hook provides environments for performing a mapping function between the asynchronous mobile station and the synchronous core network.
The asynchronous base station includes the same elements with those of the asynchronous mobile station.
Concepts of the protocol stack structure for interfacing a mobile station and a base station and a core network are already defined, however, specific functions the protocol stack structure are not yet defined and proposed.
The conventional synchronous mobile station and radio network have a disadvantage in that the synchronous mobile station cannot be interfaced with any other networks than a synchronous core network connected thereto because synchronous mobile station cannot recognize an asynchronous message from an asynchronous core network, the conventional synchronous mobile station cannot communicate with the asynchronous core network.
Similarly, the conventional asynchronous mobile station and radio network have a disadvantage in that the asynchronous mobile station cannot be interfaced with any other networks than an asynchronous core network because asynchronous mobile station cannot recognize a synchronous message from a synchronous core network, the conventional asynchronous mobile station cannot communicate with the synchronous core network.